It’s the same content, why would you need two interfaces, just because your consumers speak different languages? Because you then can change one without affect

It’s the same content, why would you need two interfaces, just because your consumers speak different languages? Because you then can change one without affecting the other. If your html is parsed automatically, the parsing can break when you update your html to fix a design flaw. OP has some good points though, those APIs look retarded. Content negotiation could be nice, but it doesn't remove the need for keys in most cases, and adding this to your stack could be harder than just making a simple API. Ask for new representations on your existing URLs. Only by embracing the information-oriented nature of the Web, we can provide sustainable access to our information for years to come Yes. But won't the answer, in most cases, be a simple "API"? (not a real API, in the programming sense)